Stretching apparatus



June 22 1926.

I 7 1,589,890 G. L. MATHER STRETGHING APPARATUS Filed March a, 1922 3 Sheets-Sheet 1- GEORGE; MA THER IN VENTOP BY 5! I ATTORNEY June 22 1926. 1,589,890

G. L. MATHER STRETCHING APPARATUS F iled March a. 1922 5 Sheets-Sheet 2 GEORGE L. MA THER INVENTOR HTTORNEY.

June 22 1926. G. L. MATHER STRETCHING APPARATUS Filed March 8, 1922 3 Sheets-Sheet 5 GEORGE MATHEP INVEN'TOR BY MW ATTORNE Patented June 2 2, 1926 UNITED STATES 1,589,890 PATENT OFFICE.

GEORGE L. MATHER, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO THE FISK RUBBER COMPANY, OF CI'IICOPEE FALLS, MASSACHUSETTS, A CORPORATION OF MASSA- CHUSETTS.

STRETCHING APPARATUS.

Application filed March 8, 1922. Serial No. 542,183.

It has been proposed to measure the stretch in fabric by measuring a function of the stretch such as the width or decrease in width and to secure uniform definite stretch by so stretching at each point that the function such as the width or decrease in width is definite and uniform throughout. My invention provides means for imparting uniform stretch by stretching to uniform width and in the drawings accompanying this specification and forming a part there of I have shown, for purposes of illustration, one form which my invention may assume. In these drawings Figure l is a side elevation of this illustrative embodiment,

Figure 2 is an end elevation thereof,

Figure 3 is a detail of the contact mechanism and circuit, while Figure 4 is a detail of the pressure cylinder.

The machine herein illustrated comprises means to tension the fabric to thereby stretch it, means to vary the tension, and means responsive to the width of the fabric to control the tension varying means to so vary the tension as to hold the stretch constant.

The mechanism for tensioning the fabric comprises a crown roll 11 over which the fabric is drawn against the resistance of a brake band 12 acting on a drum 13 mounted on a shaft 14 which also carries the roll 11 and is journalled in the frame 15. One end of the brake band 12 is secured to a fixed stud 16 and the other end to a stud 17 mounted on an elbow lever 18 pivoted at 19 to the frame 15. The tension on the brake band 12, and therefore the tension imposed on the fabric by the drum 11, is varied by movement of the lever 18.

The mechanism for varying this tension comprises a reversible motor 20 mounted upon the frame 15 and geared to a screw 21 which engages a nut 22 slidable within a cylinder 23 which is slidable upon the screw 21 and is restrained from rotation by trunnions 24 which engage the jaws 25 in the arms of a bell crank lever 26 connected by a link 27 to the elbow lever 18. A spring 28 is interposed between the nut 22 and the end 29 of the cylinder 23. It will be understood that rotation of the motor 20 in one direction will move the nut 22 toward the end 29 of the cylinder 23 to thus compress the spring 28 and urge the cylinder 23 bodily along the screw 21 to thus act through the lever 26 and link 27 to increase the pressure pushing the stud 17 upward and thus increase the tension of the brake band 12 upon the drum 13 and of the roll 11 upon the fabric, and that reverse rotation of the motor 20 will move the nut 22 in reverse direction to decrease the tensions. The operation of the motor 20 is controlled by means responsive to the width of the fabric.

From the roll 11 the fabric passes over a roll 30, under a roll 31, and thence 011. The rolls 30 and 31 are both journalled in a subframe 32 pivoted at 33 to the main frame 15. Also mounted upon the subframe 32 are a pair of rods 34 on which are mounted slides 35 and 36 each of which carries a grooved wheel 37 adapted to run against the edge of the fabric. Adjustably secured to the slide 35 by a thumb screw 38 is a rod 39 extending through the proximate edge of the slide 36 and carrying a collar 40 between which and the slide 36 is mounted a tension spring 41 acting to draw the slides 35 and 36 together. Mounted on the end of the rod 39 is a contact 42 adapted to engage either of two contacts 43 and 44 mounted upon the carriage 36 or to remain in mid-position out of engagement with both contacts.

It will be understood from the above description that the wheels 37 bear against the edges of the fabric and that the fabric therefore holds apart the slides 35 and 36 against the action of the tension spring 41 which is tending to draw the slides together. As long as the fabric is of the proper width the slides 35 and 36 will be so spaced that the contact 42 lies between the contacts 43 and 44 and disengaged from both but should the tension on the fabric prove insufficient to impart the desired stretch the width would increase and the contact 42 would be moved into engagement with the contact 44 while should the tension on the fabric become so great as to impart excessive stretch to the fabric and thus decrease the width the c011- tact 42 would be moved into engagement with the contact 43.

The motor 20 comprises an armature 45 and two field coils 46 and 47 connected in series with each other and with the armature 45 and so wound as to oppose and neutralize each other when the same current flows through both. The motor 20 is connected in series with a resistance 48 and the motor and resistance are connected to the line through switches 49, 50, and 51, and line switch 52. The contact 42 is connected to the junction of the fields 46 and 47, the contact 43 to the line side of the field 47, and the contact 44 to the line side of the field 46. Accordingly, engagement of the contacts 42 and 44 shunts thefieljd 46-to leave the field 4T unopposed and thuscause rotation of the motor 20 in a direction to increase the tension of the brake band 12 while engagements of the contacts 42. and 43 shunts the field 4'? to leave the field 46 unopposed and thus cause rotation of the motorv 20 in the reverse direction to decrease the tension of the brake band 12.

.Itwill beapparent from the above descriptionithatincrease or decrease in width of the fabric acts through the wheels 37 to engage the contact 42 with the contact 44 or the contact43 to cause operation of the motor 20 to increase or decrease the tension of the brake band: 12: tothus increase or decrease the tension applied. to the fabric until the width returns to normal. Accordingly, the above mechanism. operates to maintain uniform definite width and therefore uniform definite stretch. The adj-ustability of the rod 39 in theislide 3 5: permits adjustment to vary the normal distance between theslides 35 and 36 and accordingly-the mechanism may be set forany width to thereby function for any desired stretch in, any desired width of fab- In using. the above apparatus it is convenientto' providemeans which will prevent inadvertent operation of the motor 20. For example, when there is no fabric in the apparatus the contact 42 will immediately engage the contact 43 and continue in engagement therewith to cause the motor 20 to operate indefinitely to release the tension on the band 12.. In order to prevent this I have so pivotedthe subframe 32 that it may have a limited" movement and have provided a switch 49 mounted adjacent the subframe 32 and adaptedto be operated to open the circuit whenever the absence of fabric permits the subframe 32 to swing downwardly about'its pivot 33.

Furthermore it will be apparent that when no tension is exerted on the fabric to draw it through the stretching apparatus, there will. be no stretch of'the fabric and the full width unstretched fabric will at once cause the contact 42 to engage the contact 44 to operate the motor 20 indefinitely in a direction to tighten the band 12. To prevent this I provide a switch 50 adapted to be associated with the means which pulls the fabric through the stretching apparatus. and to be so associated as to close the circuit to the motor 20 only when the pulling means is in operation. My stretching apparatus is particularly useful for stretching the fabric used in building tires and in such case the pulling means may be the tire building machine itself which may then control the switch 50.

iVhere the stretching apparatus is employed in connection with a'tire building machine it is likely to be mounted that it may be swung out of cooperating relation. Obviously, the switch 50 is inoperative to protect the stretching apparatus unless the apparatus is cooperating with the mechanism which control-stile switch. and I accorr ingly find it convenient to interpose a further switch 51 soarranged as to be closed only when the stretching apparatus is in cooperating relation to the mechanism controlling the switch 50.

The switch may be the usual disconnecting or line switch.

iVhile I have shown and described one particular embodiment of my invention and have indicated one particular use,.the entire disclosure is illustrative only and my inventionis of course not limited thereto.

I claim:

1. A device for imparting uniform stretch to fabric comprising means to impart longitudinal tension to a moving web of fabric, means to vary the amount of tension imparted thereby and means engaging the edges of the fabric to control said last named means.

2. A device for imparting uniform stretch to fabric comprising means to impart longitudinal tension to a moving web of fabric, means for measuring, the width of the web as it leaves the tensioning means and means operatively connected to said measuring means to increase or decrease the tension applied by the first named means as the measured width rises or falls from a predetermined amount. 7 1

3. A device for imparting uniform stretch to fabric comprising means to impart longitudinal tension to a moving web of fabric, means engaging opposite edges of the web and transversely movable therewith, and means responsive to an increase or decrease in the distance between said edge engaging means to increase or decrease the degree of longitudinal tension imparted to the web.

4. Adevice for imparting uniform stretch to fabric comprising a tension roll over which a web of fabric'is adapted to pass, means engaging opposite edges of the web and transversely movable therewith, and means responsive to an increase or a decrease in the distance between said edge engaging means to increase or decrease the degree of tension applied by said roll.

5. A device for imparting uniform tension to fabric comprising a roll over which a web of'fabric is adapted to pass, means for restraining the 7 free rotation of said roll, means for measuring the width of the web as it leaves said roll and means operatively connected to said measuring means to respectively increase or decrease the restraint applied to said roll as the measured width rises or falls from a predetermined amount.

(3. A device for imparting uniform stretch to fabric comprising means for applying longitudinal tension to a moving web of fabric, means for measuring the Width of the web as it leaves the tensioning means, means operatively connected to the measuring means to increase or decrease the tension applied by the first named means as the measured Width rises or falls from a predetermined amount and means to prevent operation of the tension control mechanism in the absence of a web in the measuring means.

7. A device for imparting uniform stretch to fabric comprising a tension roll over which a Web of fabric is adapted to pass, a variable brake, operative to restrain the free rotation of the tension roll, means engaging opposite edges of the web and transversely movable therewith to measure the width of the fabric as it leaves the tension roll and means operatively connected to said brake and measuring means to respectively increase or decrease the restraint applied to the tension roll by the brake as the measured Width of the web rises or falls from a predetermined amount.

8. A device for imparting uniform stretch to fabric comprising a tension roll, provided with brake mechanism, over which a web offabric is adapted to pass a frame hinged below said tension roll and carrying means to measure the width of the web, said frame being held in raised position by the fabric web, an electric motor operatively connected to the brake mechanism to vary the restraint applied thereby to the tension roll, switches operated by the measuring means to control the operation of the motor and means cperable through lowering of the hinged frame to break the supply of current to the motor.

In testimony whereof I have signed my name to the above specification.

GEORGE L. MATHE'R. 

